The invention relates to a motor vehicle having a distance-related speed control system and having a lane departure warning system.
Such systems are known per se and usually operate independently from one another in a motor vehicle. Through lack of coordination of these systems with one another, irritating vehicle reactions may occur.
The object of the invention is to coordinate the above mentioned vehicle systems to one another in one vehicle in order to achieve uniformly predictable vehicle behavior.
This and other objects are achieved by a motor vehicle according to embodiments of the invention.
The motor vehicle according to the invention comprises a distance-related speed control system wherein if the motor vehicle is following a vehicle driving in ahead of it, a target distance, chosen by the driver, from the vehicle driving ahead of it is generally set, and wherein for a distance-shortening turn signal effect time when the turn signal is set, a shortened target distance is set. The motor vehicle according to the invention further comprises a lane departure warning system, wherein a warning that is generally activated if there is a risk of unintentional lane departure is suppressed for a specified warning-suppressing turn signal effect time after the setting of the turn signal. According to the invention, the warning-suppressing turn signal effect time begins simultaneously with the distance-shortening turn signal effect time, wherein said two turn signal effect times (time periods having a defined duration) are specified to have the same length.
The invention is based on the following considerations. Motor vehicles with the systems mentioned above are offered, for example, by the applicant. One distance-related speed control system (ACC (Adaptive Cruise Control) system) known therefrom regulates the speed to a specified target value as long as no vehicle driving ahead is located within a specified detection area in front of the vehicle. If a vehicle is located within the specified detection area in front of the vehicle in question, a target distance from the vehicle driving ahead desired by the driver is set. Here, a special distance control is also provided for a driving lane change. During a driving lane change, which is detected by a set direction indicator (turn signal), the target distance to the vehicle driving ahead of it is reduced or the distance control is terminated at the time the turn signal is set, in particular to achieve a short-term acceleration. In the former case of reduced target distance, the vehicle is accelerated to reach the now smaller target distance. This function simulates the driving behavior of a driver without a system, who already begins to accelerate in the same lane prior to overtaking After the turn signal is switched off again, the target distance is reset to the normal value. In the second case, the distance control is switched off and an acceleration control is activated. Here, the system is also given a shortened target distance as the minimum distance from the vehicle traveling ahead, upon the reaching of which the acceleration control is switched off and transferred back to the distance control.
These turn signal-dependent distance controls are ACC sub-functions in the sense of an overtaking assistance, and essentially give a temporarily shortened target distance for a time window of a certain duration, which is started by switching on the turn signal. This time window is hereinafter referred to as a “distance-shortening turn signal effect time”.
Further, lane departure warning systems for motor vehicles are known which have in an electronic control unit a function module for lane tracking (lane tracking assistant) and/or a function module to prevent a collision during lane change (lane change assistant) (e.g. “TLC”=Time to Line Crossing or “HC”=Heading Control).
Depending on defined parameters, in particular depending on the current distance of the vehicle in question to the side-limiting lane markers of the lane thereof and/or depending on the (transverse) speed with which the vehicle in question approaches the side-limiting lane markers of the lane thereof, and likewise depending on defined situations of varying degrees of danger, a visual, audible or haptic warning (e.g. by display flashing, warning tone, steering wheel vibration and/or counter-steering torque) is activated. To this end, an electronic control unit assigned to the lane departure warning system is connected with corresponding sensors and actuators.
A warning of the lane departure warning system, however, can be suppressed when an intended lane change is detected at least with a certain probability. Superfluous warnings should hereby be prevented for the relief of the driver. An intentional lane change is also recognized, for example, through setting of the turn signal. DE 102 05 225 A1 and DE 10 2008 051 700 A1 are pointed out for technical background in this regard.
In this case, a time window from the moment of turn signal activation with a specified duration for warning suppression is likewise started. This time window is hereinafter referred to as a “warning-suppressing turn signal effect time”.
According to the invention, the distance-shortening turn signal effect time and the warning-suppressing turn signal effect time are equally specified.
By means of the invention, these two time windows are coordinated with one another in order to achieve understandable reactions with respect to the setting of the turn signal.
It is thereby prevented that the lane change warning system begin to warn again although the distance-related speed control system is still driving with a shortened target distance for a harmonious overtaking maneuver. Or, it is conversely prevented that the distance-related speed control system is returned back to the normal target distance because the driver has not yet overtaken the vehicle ahead of it, however the lane change warning system continues to suppress the warning in the case that the driving lane markers are approached too closely.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.